1. Field of the Invention
The present invention relates to a liquid combination. More particularly, the present invention relates to a liquid combination for a dielectric liquid lens.
2. Description of the Prior Art
A liquid lens is a lens with an adjustable focal length. Generally, the liquid lens can be classified into electro-wetting liquid lens and dielectric liquid lens.
FIG. 1 illustrates a cross sectional view of an electro-wetting liquid lens in prior art. As shown FIG. 1, the Republic of China patent application with the publication number of 200706917 discloses an electro-wetting liquid lens 60, one end of the electro-wetting liquid lens 60 has an expansion chamber 70, which is connected with the liquid lens 60 having packing fluid 67 disposed therein so as to accommodate the fluid overflowed caused by the expansion thereof. However, the expansion chamber 70 disposed on the side surface may affect the optical design and the manufacturing process thereof. Thus, the said design shall be improved. Additionally, limited by the working principle of the electro-wetting liquid lens, the package of the electro-wetting liquid lens 60 shall be made of metal or electrical conductor, so that the selections of the materials are limited. Furthermore, because the fluid stated packaging shield thereof has a larger coefficient of temperature expansion, the liquid lens is packaged or operated with leakage when the temperature changes in environment.
The recovering speed from emulsion is one of the important performance indexes to the liquid combination. The emulsion means that two different phases which are not solvable and mixable with each other, such as water and hexane. Since the water and the hexane are not solvable with each other, the water and the hexane will be separated into two layers because of different densities. The lower density material is on top and the higher density material is at the bottom. It is the most stable condition for thermodynamic. However, while an external force is applied and one of the said liquid separated in another liquid in drop shaped, it is state of emulsion which is relatively unstable.
Please refer to the FIG. 2. FIG. 2 illustrates a schematic diagram of an emulsive liquid combination in prior art. As shown in FIG. 2, A is the phase that the material separated into drop shaped, called as dispersed phase. B is called as continuous phase. The dispersed phase A and the continuous phase B can be gas, liquid or solid. However, more compositions are required since the plurality of the requirement of the liquid combination of the liquid lens, which may cause the emulsion problem. The emulsified liquid combination 3 may cause liquid lens atomized and opaque. Accordingly, if the emulsion problem cannot be solved, the performance of the liquid lens shall be affected hugely because of the long recovering time thereof.
Accordingly, the present invention discloses a liquid combination for dielectric liquid lens so as to solve the said problem.